The backyard grilling season may be over where you are, but U.S. meat continues to come under fire.

Three recent beef recalls have roiled what millions of Americans love to have broiled. JBS Tolleson recalled close to 7 million pounds of raw beef last week due to possible Salmonella Newport contamination, while in mid-September, Cargill recalled an estimated 132,000 pounds due to concerns about E. coli O26, according to the U.S. Department of Agriculture. August saw the supermarket chain Publix recall an undetermined amount of ground beef potentially contaminated with E. coli in Florida.

"Cooking food thoroughly and handling it correctly is critically important," said Carmen Rottenberg, acting deputy undersecretary for the USDA's Office for Food Safety. "The food produced is not sterile ... People want to cook raw food and prepare it at home. If you prepare it at home, you have to know there are some risks associated with it."

The hamburger, as national a food as apple pie, is the image this country has exported around the globe for half century. Equally iconic is meatloaf, a comfort food from June Cleaver that's made a hipster, deconstructed comeback. Meatball subs and meat-lovers pizza have a place at every football viewing party.

The beef industry says it's reducing foodborne pathogens at every stage of the supply chain.

"Since 1993, cattle farmers and ranchers have invested tens of millions of dollars in safety research programs and the industry as a whole invests over $500 million annually in beef safety research, testing and technology implementation," the National Cattlemen’s Beef Association, said in an e-mail. "Nothing is more important to the beef industry than the safety of our consumers."

Here's why the staple of the all-American diet from chuck wagons that fed the 19th century cowboys in the Wild West to the growing so-called "better burger" restaurants is so susceptible.

The melting pot, er, mixing bowl

Unlike unprocessed produce or whole cuts of meat, ground beef is made up of bits and pieces from many different animals – each one with the potential to taint the whole batch.

"When you buy a chicken breast, how many animals is that? One. Ground beef? As many as 400 animals in commercially processed beef," said Northeastern University food safety expert Darin Detwiler. "Unless you buy steak from the grocer and grind it up yourself, you're talking about Russian roulette."

If equipment isn't cleaned well between runs, the residue could contaminate the next production cycle, too.

A complicated production line

The giant vats of mixed meat are just one part of the production process; multiple steps equals multiple potential problems. Each point along the way – from the farm to the finished product – is a chance for pathogens to enter.

Detwiler says the trouble can begin when the cows are still alive – on corporate farms, in confined spaces and walking around in fecal matter, which is how many pathogens are transmitted.

From there, they go to what are euphemistically called processing facilities.

"The slaughtering of animals is a very dirty process in ways tomatoes are not," said Brian Kellerman, a Columbus, Ohio-based food-safety consultant. "It’s dirty in the field, but once you dig it out, you wash and that’s it. With animals, all the blood and innards required to be to removed has the potential to contaminate."

Plenty in the land of plenty

The expression "meat and potatoes" isn't used to mean "basic" for nothing. Meat is a fundamental part of what many of us eat daily from breakfast patties to late-night taco runs.

Americans will consume 59.1 pounds of beef per capita in 2018, according to the USDA's forecast. That's up from 54 pounds in 2015.

Chances are, it's in your fridge or freezer as you read this. This food is universal in a way that romaine lettuce, recalled early this year in massive campaign from Yuma, Ariz., isn't. Its pervasiveness in our diets makes it harder to root out.

A greater risk

More is at stake when it comes to chopped steak. E. coli can kill people, especially children, the elderly and people with compromised immune systems. The Jack in the Box E. coli outbreak in 1993 brought the issue into the national consciousness, as more than 700 people got sick and four children died. In the interim quarter of a century, Americans have become more knowledgeable about foodborne illnesses – and other pathogens, such as listeria and salmonella.

"We have certain situations where we assume there's always a chance there’s a danger, but don’t ever have that awareness when comes to food," said Detwiler, whose 16-month-old son Riley was one of the Jack in the Box fatalities. "It seems like there's a daily, weekly, monthly reminder of those rude awakenings. We have to start paying attention."

A false sense of security

To avoid contracting a foodborne illness from fruits and vegetables, you wash them before eating, but ensuring your beef is safe to consume requires thorough cooking. Not everyone does that – or even knows how to.

The Centers for Disease Control and Prevention advises cooking ground beef to a minimum internal temperature of 160°F and always using a food thermometer to make sure it's hit that heat threshold.

Leaving this vital part of food safety – what experts call the kill step – up to laypeople in their kitchens and backyards is perilous. The USDA's Rottenberg said the department is trying to improve on that.

"There's more work to be done on the public education front," she said, adding that the department also is conducting studies on what people really do behind closed doors while cooking.

Not every home chef or griller has a meat thermometer, and eyeballing ground beef is unreliable. Searing it on the outside, which is acceptable for a steak, doesn't work here, because the pathogen could be inside the burger. Another no-no is putting a cooked burger back on the plate you'd used for the raw meat. And be sure to wash your hands and sanitize all surfaces, including counter tops and cutting boards, after contact with raw meat.

"Any person who likes their hamburgers medium rare is taking an enormous risk. If it's contaminated beef, they will not reach a temperature that will get rid of the pathogen," Kellerman said. "People's cooking skills may be deficient. They may not understand how to handle meats, even though it’s common knowledge."